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You searched for: subject:"Fourier transformation"
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[texts]Molecular nitrogen in the upper atmosphere - Danilov, A. D
No Abstract Available
Keywords: CALIBRATING; SHOCK TUBES; FOURIER TRANSFORMATION; PRESSURE SENSORS
Downloads: 51
[texts]A controlled variation scheme for convection treatment in pressure-based algorithm - Shyy, Wei
Convection effect and source terms are two primary sources of difficulties in computing turbulent reacting flows typically encountered in propulsion devices. The present work intends to elucidate the individual as well as the collective roles of convection and source terms in the fluid flow equations, and to devise appropriate treatments and implementations to improve our current capability of predicting such flows...
Keywords: FOURIER TRANSFORMATION; LORENTZ TRANSFORMATIONS; OPERATORS (MATHEMATICS); QUANTUM MECHANICS; ROTATION
Downloads: 65
[texts]Aerodynamic design optimization using sensitivity analysis and computational fluid dynamics - NON
An efficient aerodynamic shape optimization method based on a computational fluid dynamics/sensitivity analysis algorithm has been developed which determines automatically the geometrical definition of an optimal surface starting from any initial arbitrary geometry. This method is not limited to any number of design variables or to any class of surfaces for shape definition.
Keywords: ALGEBRA; CODING; COMPUTERS; FOURIER TRANSFORMATION; VIRTUAL MEMORY SYSTEMS; ALGORITHMS; FORTRAN
Downloads: 239
[texts]A Selected Annotated Bibliography on Martian Exploration - Launius, Roger D
This document is a selected annotated bibliography on martian exploration.
Keywords: FREQUENCY DIVISION MULTIPLEXING; WAVEFORMS; DATA SYSTEMS; FOURIER TRANSFORMATION; DISCRETE FUNCTIONS
Downloads: 63
[texts]The Southern Hemisphere Additional Ozonesondes (SHADOZ) 1998-2002 Tropical Ozone Climatology - Thompson, Anne M.
Abstract: Since 1998 the Southern Hemisphere ADditional OZonesondes (SHADOZ) project has collected more than 2000 ozone profiles from a dozen tropical and subtropical sites using balloon-borne electrochemical concentration cell (ECC) ozonesondes. The data (with accompanying pressure-temperature-humidity soundings) are archived. Analysis of ozonesonde imprecision within the SHADOZ dataset revealed that variations in ozonesonde technique could lead to station-to-station biases in the measurements...
Keywords: ASTRONOMICAL INTERFEROMETRY; MICHELSON INTERFEROMETERS; DATA PROCESSING; FOURIER TRANSFORMATION; INFRARED TELESCOPES; COHERENT LIGHT; OPTICAL PATHS
Downloads: 63
[texts]Observations of waterspouts and their parent clouds - Rossow, V. J
Observations of waterspouts and their parent clouds
Keywords: DATA CORRELATION; DIGITAL FILTERS; COMPUTER PROGRAMMING; FOURIER TRANSFORMATION; FREQUENCY RANGES; SIGNAL TO NOISE RATIOS; SPECTRUM ANALYSIS
Downloads: 85
[texts]COLLECTION OF PROBLEMS ON THE DYNAMICS OF A POINT IN A CENTRAL FORCE FIELD - POLYAKHOVA, Y. N
A DETAILED SELECTION OF PROBLEMS ON THE DYNAMICS OF THE MOTION OF A MATERIAL POINT ACTED ON BY A CENTRAL GRAVITATIONAL FORCE, IN PARTICULAR, THE DYNAMICS OF SPACE FLIGHT IS PRESENTED ALONG WITH SEVERAL PROBLEMS ON THE MOTION OF A POINT ACTED ON BY CENTRAL NONGRAVITATIONAL FORCES. TOPICS COVERED INCLUDE KEPLER'S LAWS, BINET'S FORMULAS FOR CENTRAL FORCES, THE ENERGY BALANCE AND VELOCITY ALONG A SPACE TRAJECTORY, TIME OF MOTION ALONG A SPACE TRAJECTORY, CONDITIONS FOR THE EXISTENCE OF ELLIPTICAL TR...
Keywords: LATTICE PARAMETERS; POISSON EQUATION; SOLID STATE PHYSICS; SUM RULES; CESIUM COMPOUNDS; CHLORIDES; ELECTRIC FIELDS; FOURIER TRANSFORMATION
Downloads: 234
[texts]Plate Deformation Behavior of Polymer Matrix Composite-Ti Honeycomb-Metal Sandwiches for Pressurized Propulsion Component Applications - Bertelsen, William D.
THe objectives are: 1. To experimentally validate bi-axial plate flexural performance of PMC-Ti H/C-A286 sandwich panels for the internally pressurized RBCC combustion chamber support structure. 2. To explore ASTM 2-D plate flexure test (D 6416) to simulate the internal pressure loading and to correlate the results with analytical and FE modeling based on 2-D flexure properties.
Keywords: THERMOGRAPHY; FOURIER TRANSFORMATION; PHASE CONTRAST; IMAGE PROCESSING; THREE DIMENSIONAL MODELS; NONDESTRUCTIVE TESTS; MATHEMATICAL MODELS
Downloads: 141
[texts]On some numerical difficulties in integrating the equations for one-dimensional nonequilibrium nozzle flow - Bailey, H. E.
Numerical difficulties in integrating equations for one dimensional nonequilibrium nozzle flow of gas
Keywords: SPACECRAFT; STRUCTURAL ANALYSIS; TRANSFER FUNCTIONS; DYNAMIC RESPONSE; FOURIER TRANSFORMATION; GRAPHS (CHARTS); RANDOM PROCESSES; SYSTEMS ENGINEERING
Downloads: 54
[texts]Thermal-structural panel buckling tests - Thompson, Randolph C.
The buckling characteristics of a titanium matrix composite hat-stiffened panel were experimentally examined for various combinations of thermal and mechanical loads. Panel failure was prevented by maintaining the applied loads below real-time critical buckling predictions. The test techniques used to apply the loads, minimize boundary were shown to compare well with a finite-element buckling analysis for previous panels...
Keywords: ATMOSPHERIC COMPOSITION; HIGH RESOLUTION; LOW NOISE; SPECTRAL RESOLUTION; SPECTROSCOPIC ANALYSIS; SPECTROSCOPY; UPPER ATMOSPHERE; FOURIER TRANSFORMATION; SPECTROMETERS
Downloads: 107
[texts]An Inviscid Computational Study of the Space Shuttle Orbiter and Several Damaged Configurations - Prabhu, Ramadas K.
Inviscid aerodynamic characteristics of the Space Shuttle Orbiter were computed in support of the Columbia Accident Investigation. The unstructured grid software FELISA was used and computations were done using freestream conditions corresponding to those in the NASA Langley 20-Inch Mach 6 CF4 tunnel test section. The angle of attack was held constant at 40 degrees. The baseline (undamaged) configuration and a large number of damaged configurations of the Orbiter were studied...
Keywords: INFRARED SPECTROMETERS; FOURIER TRANSFORMATION; LINEAR SYSTEMS; OPTICAL PATHS; INTERFEROMETERS; SPECTRAL RESOLUTION; PLANETARY ATMOSPHERES; MISALIGNMENT
Downloads: 116
[texts]On the use of hydrogen peroxide as oxidizer in hybrid systems - Pugibet, M., et al
Hydrogen peroxide as oxidizer in hybrid propellant rocket engines
Keywords: ATMOSPHERIC CIRCULATION; BEAMS (RADIATION); CROSS CORRELATION; SPECTRUM ANALYSIS; FOURIER TRANSFORMATION; MATHEMATICAL MODELS; PULSE AMPLITUDE; TIME LAG
Downloads: 149
[texts]Flight Dynamics Analysis Branch End of Fiscal Year 1999 Report - Stengle, Thomas
This document summarizes the major activities and accomplishments carried out by the Goddard Space Flight Center (GSFC)'s Flight Dynamics Analysis Branch (FDAB), Code 572, in support of flight projects and technology development initiatives in Fiscal Year (FY) 1999. The document is intended to serve as both an introduction to the type of support carried out by the FDAB (Flight Dynamics Analysis Branch), as well as a concise reference summarizing key analysis results and mission experience derive...
Keywords: SIGNAL PROCESSING; VERY LARGE SCALE INTEGRATION; SYSTOLIC ARRAYS; PARALLEL PROCESSING (COMPUTERS); FOURIER TRANSFORMATION; WAVELET ANALYSIS; BANDWIDTH
Downloads: 85
[texts]IN REGARD TO BACTERIAL REDUCTION OF ORGANICALLY BOUND PHOSPHORIC ACID - BARRENSCHEEN, H. K.
BLONDLOT-DUSART TESTS ON PUTRID BLOOD GIVE IRREPROACHABLE PROOF THAT BACTERIA UNDER ANAEROBIC CONDITIONS AT SUITABLE TEMPERATURE ARE CAPABLE OF REDUCING ORGANICALLY BOUND PHOSPHORIC ACID SUFFICIENTLY SO AS TO OBTAIN A POSITIVE REACTION. EXPERIMENTS PERFORMED ON HUMAN OR CANINE BLOOD OBTAINED UNDER STERILE PRECAUTIONS PROVE COMPLETELY NEGATIVE AND IT IS CONCLUDED THAT THE OPTIONAL ANAEROBIANTS EXAMINED - AND BELONGING TO THE PROTEUS GROUP - ARE BY THEMSELVES NOT CAPABLE FOR THE REDUCTION OF PHOSP...
Keywords: CLOUD PHOTOGRAPHS; NIMBUS 4 SATELLITE; WIND (METEOROLOGY); CROSS CORRELATION; ERROR ANALYSIS; FOURIER TRANSFORMATION; IMAGING TECHNIQUES
Downloads: 87
[texts]High Gain Antenna Gimbal for the 2003-2004 Mars Exploration Rover Program - Sokol, Jeff
The High Gain Antenna Assemblies built for the 2003-2004 Mars Exploration Rover (MER) missions provide the primary communication link for the Rovers once they arrive on Mars. The High Gain Antenna Gimbal (HGAG) portion of the assembly is a two-axis gimbal that provides the structural support, pointing, and tracking for the High Gain Antenna (HGA). The MER mission requirements provided some unique design challenges for the HGAG...
Keywords: MICROWAVE INTERFEROMETERS; FOURIER TRANSFORMATION; IMAGING TECHNIQUES; MICROWAVE IMAGERY; THEOREMS; SCALARS; REMOTE SENSING; POLARIMETRY
Downloads: 93
[texts]Ionizing radiations and parameters modifying radiation sterilization - NON
No Abstract Available
Keywords: COMPUTATION; EQUATIONS OF MOTION; PERTURBATION; FOURIER SERIES; FOURIER TRANSFORMATION; JACOBI INTEGRAL; MATHEMATICAL MODELS; PERIODIC VARIATIONS
Downloads: 69
[texts]Three-dimensional viscous flow analysis inside a turbine volute - Hah, C.
A three-dimensional numerical method has been developed to analyze the complex flow field inside a turbine volute. Comparisons are made between solutions with different boundary conditions.
Keywords: FOURIER TRANSFORMATION; HARMONIC OSCILLATION; ORTHOGONAL FUNCTIONS; POLYNOMIALS; WAVE FUNCTIONS; INTEGRALS; ORTHOGONALITY
Downloads: 94
[texts]Parallel software tools at Langley Research Center - Moitra, Stuti
This document gives a brief overview of parallel software tools available on the Intel iPSC/860 parallel computer at Langley Research Center. It is intended to provide a source of information that is somewhat more concise than vendor-supplied material on the purpose and use of various tools. Each of the chapters on tools is organized in a similar manner covering an overview of the functionality, access information, how to effectively use the tool, observations about the tool and how it compares ...
Keywords: HARMONIC OSCILLATORS; HEISENBERG THEORY; QUANTUM MECHANICS; EIGENVECTORS; FOURIER TRANSFORMATION; HERMITIAN POLYNOMIAL
Downloads: 104
[texts]Space Resource Requirements for Future In-Space Propellant Production Depots - Smitherman, David
In 2000 and 2001 studies were conducted at the NASA Marshall Space Flight Center on the technical requirements and commercial potential for propellant production depots in low Earth orbit (LEO) to support future commercial, NASA, and other Agency missions. Results indicate that propellant production depots appear to be technically feasible given continued technology development, and there is a substantial growing market that depots could support...
Keywords: ALGORITHMS; DIFFRACTION PATTERNS; FRICTION MEASUREMENT; SKIN FRICTION; DETECTION; FOURIER TRANSFORMATION; INTERFEROMETRY
Downloads: 117
[movies]MIT RES.6-008 Digital Signal Processing, 1975
Instructor: Alan V. Oppenheim Set of 20 video lectures for Signals and Systems, an introductory course in analog and digital signal processing, including seismic data processing, communications, speech processing, image processing, consumer electronics, and defense electronics. View the complete course: http://ocw.mit.edu/RES6-008S11 License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
Keywords: signal processing; analog systems; digital systems; feedback; discrete-time signals; continuous-time signals; modulation; Fourier transformation
Downloads: 23,844
[texts]Apollo reentry guidance and navigation equations and flow logic - Hunt, G. L
No Abstract Available
Keywords: RANDOM PROCESSES; WHITE NOISE; ALGORITHMS; BROADBAND; COMPUTERIZED SIMULATION; FOURIER TRANSFORMATION; NOISE INTENSITY; SPECTRAL ENERGY DISTRIBUTION
Downloads: 259
[texts]Multiphoton Process and Anomalous Potential of Cell Membrane by Laser Radiation - Zhang, Kaixi
In this paper, by the use of quantum biology and quantum optics, the laser induced potential variation of cell membrane has been studied. Theoretically, we have found a method of calculating the monophoton and multiphoton processes in the formation of the anomalous potential of cell membrane. In contrast with the experimental results, our numerical result is in the same order. Therefore, we have found the possibility of cancer caused by the laser induced anomalous cell potential.
Keywords: QUANTUM MECHANICS; WAVE FUNCTIONS; FOURIER TRANSFORMATION; VELOCITY; VELOCITY MEASUREMENT; PARTICLE ACCELERATION; EIGENVECTORS
Downloads: 75
[texts]Operations and facilities - DSN operations - NON
Deep Space Stations configured as phase sensitive interferometer to measure apparent change in angular separation between radio sources near time of occultation by sun
Keywords: JET FLOW; SHEAR LAYERS; STRATA; CLEAR AIR TURBULENCE; DIFFERENTIAL EQUATIONS; FOURIER TRANSFORMATION; INTEGRAL EQUATIONS
Downloads: 127
[texts]Water measurement support for Goddard Space Flight Center spectrometer water color study: Mississippi sound area, 24 July 1972 - Weldon, J. W
No Abstract Available
Keywords: COMPENSATORY TRACKING; FOURIER TRANSFORMATION; LEAST SQUARES METHOD; OPERATOR PERFORMANCE; ERROR SIGNALS; ON-LINE SYSTEMS; SINE WAVES; TRANSFER FUNCTIONS
Downloads: 53
[texts]Tissue Culture in Microgravity - Pellis, Neal R.
Attempts to simulate normal tissue micro-environments in vitro have been thwarted by the complexity and plasticity of the extracellular matrix, which is important in regulating cytoskeletal and nuclear matrix proteins. Gravity is one of the problems, tending to separate components that should be kept together. For space shuttle experiments, NASA engineers devised a double-walled rotating bioreactor, which is proving to be a useful tissue culture device on earth as well as in space.
Keywords: NOCTURNAL VARIATIONS; HARMONIC ANALYSIS; OSCILLATIONS; MESOSPHERE; HYDROXYL EMISSION; FOURIER TRANSFORMATION; ANNUAL VARIATIONS; PERIODIC FUNCTIONS; NEAR INFRARED RADIATION; INFRARED SPECTRA
Downloads: 93
[texts]Virtex-II Pro SEE Test Methods and Results - Petrick, David
The objective of this coarse Single Event Effect (SEE) test is to determine the suitability of the commercial Virtex-II Pro family for use in spaceflight applications. To this end, this test is primarily intended to determine any Singe Event Latchup (SEL) susceptibilities for these devices. Secondly, this test is intended to measure the level of Single Event Upset (SEU) susceptibilities and in a general sense where they occur...
Keywords: PHASE LOCKED SYSTEMS; SHOCK FRONTS; LISA (OBSERVATORY); INTERFEROMETERS; LIGHT BEAMS; SHOT NOISE; TEMPERATURE EFFECTS; FOURIER TRANSFORMATION; YAG LASERS; NEODYMIUM LASERS
Downloads: 53
[texts]Some aspects of noise analysis of interferometer spectrometers - Augason, G. C.
Distribution of noise spectrum obtained by Fourier transform of interferogram - use of sampling theory and statistical methods
Keywords: FOURIER TRANSFORMATION; NOISE SPECTRUM; SAMPLING; STATISTICAL ANALYSIS; INTERFEROMETERS; INTERFEROMETRY; NOISE SPECTRA; SAMPLING; SPECTROMETERS; STATISTICAL ANALYSIS; FOURIER TRANSFORM; INTERFEROMETER
Downloads: 95
[texts]New polymers for phase partitioning - Harris, J. M
The synthesizing of several polyethylene glycols having crown ethers attached is reported. This work led to the identification of three new polymer types which promise to be more effective at selectively binding specific cell types. Work was completed on identification of chemical properties of the new polymer crowns and on development of new techniques for determination of polymer-phase composition.
Keywords: EMISSION SPECTRA; PLANETARY ATMOSPHERES; REMOTE SENSING; FOURIER TRANSFORMATION; INFRARED SPECTROMETERS; PLANETOLOGY; SPACE EXPLORATION; VOYAGER PROJECT; CALIBRATING; INFRARED INTERFEROMETERS; NATURAL SATELLITES
Downloads: 78
[texts]Large scale dynamic systems - Doolin, B. F
Classes of large scale dynamic systems were discussed in the context of modern control theory. Specific examples discussed were in the technical fields of aeronautics, water resources and electric power.
Keywords: BBGKY HIERARCHY; VISCOUS DAMPING; KINETIC THEORY; PROBABILITY DISTRIBUTION FUNCTIONS; TURBULENT FLOW; APPROXIMATION; CONSERVATION LAWS; CORRELATION; FOKKER-PLANCK EQUATION; FOURIER TRANSFORMATION
Downloads: 192
[texts]Satellite Studies of Storm-Time Thermospheric Winds - Fejer, Bela G
In this project we have studied the climatology and storm-time dependence of longitude-averaged mid- and low-latitude thermospheric neutral winds observed by the WINDII instrument on board the UARS satellite. This satellite is in a circular, 57 deg inclination orbit at a height of 585 km; the orbit precesses at a rate of 5 deg per day. WINDII is a Michelson interferometer that measures Doppler shifts of the green line (557.7 nm) and red line (630.0 nm) airglow emissions at the Earth's limb, cove...
Keywords: ATMOSPHERIC SOUNDING; INFRARED INSTRUMENTS; IMAGING SPECTROMETERS; REMOTE CONTROL; FOURIER TRANSFORMATION; ATMOSPHERIC TEMPERATURE; ATMOSPHERIC COMPOSITION; OZONE; WIND (METEOROLOGY)
Downloads: 66
[texts]The Aperture Admittance of a Ground Plane Mounted Waveguide Illuminating a Perfectly Conducting Sheet - Jones, J. E.
Fourier transforms for aperture admittance of ground-plane-mounted waveguide illuminating conducting sheet
Keywords: APERTURES; WAVE REFLECTION; FOURIER TRANSFORMATION; WAVEGUIDES; ELECTRIC FIELDS; MAGNETIC FIELDS; MATHEMATICAL MODELS; PARALLEL PLATES; PROPAGATION MODES; REFLECTANCE
Downloads: 116
[texts]Design of a power management and distribution system for a thermionic-diode powered spacecraft - Kimnach, Greg L
The Electrical Systems Development Branch of the Power Technology Division at the NASA Lewis Research Center in Cleveland, Ohio is designing a Power Management and Distribution (PMAD) System for the Air Force's Integrated Solar Upper Stage (ISUS) Engine Ground Test Demonstration (EGD). The ISUS program uses solar-thermal propulsion to perform orbit transfers from Low Earth Orbit (LEO) to Geosynchronous Orbit (GEO) and from LEO to Molnya...
Keywords: ULTRASONICS; RECTIFICATION; FOURIER TRANSFORMATION; TISSUES (BIOLOGY); HISTOCHEMICAL ANALYSIS; CHARACTERIZATION; ULTRASONIC TESTS; PATENT APPLICATIONS; HISTOLOGY; CELLS (BIOLOGY); QUANTITATIVE ANALYSIS
Downloads: 81
[texts]A Study of Joint Fixativity in a Joined-Wing Aircraft - OBanion, Jack
The present study was initiated to compare the stress distributions in a joined-wing structure that result from employing seven different wing-joint fixativities. The joint fixativity refers to the type of attachment that connects the leading-edge tip of the rear wing to the outboard portion of the forward wing trailing edge. The analysis determines the best wing-joint fixativity of a statically loaded idealized joined-wing configuration...
Keywords: METHANE; TROPOPAUSE; TROPOSPHERE; OXIDATION; VERTICAL DISTRIBUTION; NORTHERN HEMISPHERE; STRATOSPHERE; WATER VAPOR; ALTITUDE; FOURIER TRANSFORMATION; MIXING RATIOS; SPECTROMETERS; SPECTROSCOPY
Downloads: 165
[texts]Fundamental aspects in the quantitative ultrasonic determination of fracture toughness: General equations - Fu, L. S
The problem of establishing a theoretical groundwork for experimentally-found correlations between ultrasonic and fracture toughness factors in polycrystalline metals is discussed. It is noted that the link between these material properties and ultrasonic factors are the microstructural parameters that interact with stress wave propagation during deformation and fracture. The dynamic response of material inhomogeneities and the strains and displacements they undergo under incident stress waves a...
Keywords: ERROR ANALYSIS; RADIO INTERFEROMETERS; RADIO SOURCES (ASTRONOMY); TIME MEASUREMENT; FOURIER TRANSFORMATION; SKY BRIGHTNESS; VERY LONG BASE INTERFEROMETRY
Downloads: 92
[texts]Measurements and Modeling of Soot Formation and Radiation in Microgravity Jet Diffusion Flames - Ku, Jerry C.
This is a computational and experimental study for soot formation and radiative heat transfer in jet diffusion flames under normal gravity (1-g) and microgravity (0-g) conditions. Instantaneous soot volume fraction maps are measured using a full-field imaging absorption technique developed by the authors. A compact, self-contained drop rig is used for microgravity experiments in the 2.2-second drop tower facility at NASA Lewis Research Center...
Keywords: SYSTEM IDENTIFICATION; FOURIER TRANSFORMATION; FREQUENCIES; FLIGHT TESTS; SAMPLED DATA SYSTEMS; RESEARCH VEHICLES; SIGNAL PROCESSING; INTERPOLATION; F-18 AIRCRAFT
Downloads: 97
[texts]Design-Oriented Analysis of Aircraft Fuselage Structures - Giles, Gary L
A design-oriented analysis capability for aircraft fuselage structures that utilizes equivalent plate methodology is described. This new capability is implemented as an addition to the existing wing analysis procedure in the Equivalent Laminated Plate Solution (ELAPS) computer code. The wing and fuselage analyses are combined to model entire airframes. The paper focuses on the fuselage model definition, the associated analytical formulation and the approach used to couple the wing and fuselage a...
Keywords: REAL TIME OPERATION; RESONANT FREQUENCIES; DYNAMIC MODELS; DYNAMIC RESPONSE; ERRORS; FOURIER TRANSFORMATION; RESEARCH VEHICLES; ADAPTIVE CONTROL; CONTROL SURFACES; AIRCRAFT MODELS
Downloads: 294
[texts]Improved computer simulation of the TCAS 3 circular array mounted on an aircraft - Rojas, R. G.
The Traffic advisory and Collision Avoidance System (TCAS) is being developed by the Federal Aviation Administration (FAA) to assist aircraft pilots in mid-air collision avoidance. This report concentrates on the computer simulation of the enchanced TCAS 2 systems mounted on a Boeing 727. First, the moment method is used to obtain an accurate model for the enhanced TCAS 2 antenna array. Then, the OSU Aircraft Code is used to generate theoretical radiation patterns of this model mounted on a simu...
Keywords: FORMALDEHYDE; FOURIER TRANSFORMATION; INFRARED SPECTROSCOPY; MOLECULAR SPECTROSCOPY; TUNABLE LASERS; BAND STRUCTURE OF SOLIDS; EIGENVECTORS; MOLECULAR SPECTRA; NUMERICAL ANALYSIS
Downloads: 130
[texts]Lubricating Properties of Ceramic-Bonded Calcium Fluoride Coatings on Nickel-Base Alloys from 75 to 1900 deg F - Sliney, Harold E
The endurance life and the friction coefficient of ceramic-bonded calcium fluoride (CaF2) coatings on nickel-base alloys were determined at temperatures from 75 F to 1900 F. The specimen configuration consisted of a hemispherical rider (3/16-in. rad.) sliding against the flat surface of a rotating disk. Increasing the ambient temperature (up to 1500 F) or the sliding velocity generally reduced the friction coefficient and improved coating life...
Keywords: INCOMPRESSIBLE BOUNDARY LAYER; CONTINUOUS SPECTRA; FOURIER TRANSFORMATION; FLOW STABILITY; HYDRODYNAMIC COEFFICIENTS; VIBRATION; RIBBONS; HYDRODYNAMIC EQUATIONS; SINGULARITY (MATHEMATICS); COMPLEX NUMBERS
Downloads: 88
[texts]Spectral characteristics of air at temperatures above 10000 degrees Kelvin - Konkov, A. A., et al
Spectral characteristics of air at high temperatures
Keywords: BANDWIDTH; MONOCHROMATIC RADIATION; LUNAR OCCULTATION; MATHEMATICAL MODELS; RADIO ASTRONOMY; BANDPASS FILTERS; BEAMS (RADIATION); FOURIER TRANSFORMATION; FRESNEL INTEGRALS; GAUSS EQUATION
Downloads: 76
[texts]Carbon isotopes in oil-gas geology - Galimov, E. M
Analysis of variations in the natural abundances of the carbon isotopes C12 and C13 in petroleum, gases, bitumens, and other materials is treated. A theoretical-calculation division gives data on the thermodynamic isotope effects of organic compounds, and presents a theory of biogenic isotope equilibria and intramolecular isotope nonuniformity of bio-organic compounds. Laboratory studies of processes simulating natural fractionation of carbon isotopes are emphasized; included are data on the iso...
Keywords: BOUNDARY LAYERS; RADAR CROSS SECTIONS; ELECTROMAGNETIC RADIATION; SEA ICE; WAVE SCATTERING; BACKSCATTERING; BOUNDARY CONDITIONS; DIFFERENTIAL EQUATIONS; FOURIER TRANSFORMATION; PERTURBATION THEORY
Downloads: 328
[texts]Pre-Hardware Optimization and Implementation Of Fast Optics Closed Control Loop Algorithms - Kizhner, Semion
One of the main heritage tools used in scientific and engineering data spectrum analysis is the Fourier Integral Transform and its high performance digital equivalent - the Fast Fourier Transform (FFT). The FFT is particularly useful in two-dimensional (2-D) image processing (FFT2) within optical systems control. However, timing constraints of a fast optics closed control loop would require a supercomputer to run the software implementation of the FFT2 and its inverse, as well as other image pro...
Keywords: HYDROGEN; INFRARED SPECTROSCOPY; PYROXENES; SILICATES; FELDSPARS; IRON; OXYGEN; MINERALOGY; MARS SURFACE; SNC METEORITES; VELOCITY DISTRIBUTION; FOURIER TRANSFORMATION; MELTS (CRYSTAL GROWTH)
Downloads: 117
[texts]Debris/Ice/TPS Assessment and Integrated Photographic Analysis of Shuttle Mission STS-82 - Katnik, Gregory N.
A debris/ice/thermal protection system assessment and integrated photographic analysis was conducted for Shuttle mission STS-82. Debris inspections of the flight elements and launch pad were performed before and after launch. Icing conditions on the External Tank were assessed by the use of computer programs and infrared scanned data during cryogenic loading of the vehicle, followed by on-pad visual inspection...
Keywords: FOURIER TRANSFORMATION; TRIGONOMETRIC FUNCTIONS; INTEGERS; DETECTION; APPLICATIONS PROGRAMS (COMPUTERS); HIGH RESOLUTION; DISCRETE FUNCTIONS; ALGORITHMS; COMPUTATION; INTERPOLATION; PERIODIC VARIATIONS; SEQUENCING
Downloads: 78
[texts]The Integration of COTS/GOTS within NASA's HST Command and Control System - Pfarr, Thomas
NASA's mission critical Hubble Space Telescope (HST) command and control system has been re-engineered with commercial-off-the-shelf (COTS/GOTS) and minimal custom code. This paper focuses on the design of this new HST Control Center System (CCS) and the lessons learned throughout its development. CCS currently utilizes more than 30 COTS/GOTS products with an additional 1/2 million lines of custom glueware code; the new CCS exceeds the capabilities of the original system while significantly redu...
Keywords: HIGH RESOLUTION; INFRARED SPECTROSCOPY; MOLECULES; PLANETARY ATMOSPHERES; EARTH ATMOSPHERE; CHEMICAL COMPOSITION; FOURIER TRANSFORMATION; ATMOSPHERIC PHYSICS; SPECTRUM ANALYSIS
Downloads: 105
[texts]Poly(arylene ether imidazole) surfacing films for flat and parabolic structures - NON
Films of thermoplastic poly(arylene ether imidazole)s (PAEIs) are used as surface modifiers for neat resin panels and composite resin panels. The PAEI polymer contains imidazole groups along the backbone which co-cure, i.e., react chemically, with epoxies or bismaleimides during processing and thereby provide excellent adhesion between the PAEI film and an epoxy or bismaleimide neat resin or composite resin facesheet...
Keywords: CONTROL THEORY; MUSCLES; ELBOW (ANATOMY); MUSCULAR FUNCTION; STIFFNESS; TRANSFER FUNCTIONS; ACTIVATION (BIOLOGY); CONTROL SYSTEMS DESIGN; DYNAMIC RESPONSE; FOURIER TRANSFORMATION
Downloads: 146
[texts]Combined Lidar-Radar Remote Sensing: Initial Results from CRYSTAL-FACE and Implications for Future Spaceflight Missions - McGill, Matthew J.
In the near future NASA plans to fly satellites carrying a multi-wavelength backscatter lidar and a 94-GHz cloud profiling radar in formation to provide complete global profiling of cloud and aerosol properties. The CRYSTAL-FACE field campaign, conducted during July 2002, provided the first high-altitude colocated measurements from lidar and cloud profiling radar to simulate these spaceborne sensors...
Keywords: GAMMA RAY ABSORPTION; FOURIER TRANSFORMATION; FREQUENCIES; NUCLEAR DEVICES; RADIOACTIVE DECAY; IMAGING TECHNIQUES; GAMMA RAYS; NUCLEAR WARHEADS; PENETRATION; NUMERICAL ANALYSIS; NEUTRONS; DIFFRACTION PATTERNS; EMITTANCE; FLYING PLATFORMS
Downloads: 95
[texts]Evaluation of Perspective and Coplanar Cockpit Displays of Traffic Information to Support Hazard Awareness in Free Flight - Merwin, David H.
We examined the cockpit display representation of traffic, to support the pilot in tactical planning and conflict avoidance. Such displays may support the ''free flight'' concept, but can also support greater situation awareness in a non-free flight environment. Two perspective views and a coplanar display were contrasted in scenarios in which pilots needed to navigate around conflicting traffic, either in the absence (low workload) or presence (high workload) of a second intruder aircraft...
Keywords: WAVE FRONTS; BREADBOARD MODELS; REFLECTANCE; ALIGNMENT; MODULATION; RADAR CORNER REFLECTORS; ERRORS; DEFOCUSING; SHEARS; INFRARED SPECTROMETERS; FOURIER TRANSFORMATION; CASSINI MISSION; CORNERS; RETROREFLECTORS
Downloads: 64
[texts]A fundamental study of the sticking of insect residues to aircraft wings - Eiss, N. S., Jr.
The aircraft industry has long been concerned with the increase of drag on airplanes due to fouling of the wings by insects. The present research studied the effects of surface energy and surface roughness on the phenomenon of insect sticking. Aluminum plates of different roughnesses were coated with thin films of polymers with varying surface energies. The coated plates were attached to a custom jig and mounted on top of an automobile for insect collection...
Keywords: IMAGING TECHNIQUES; SURVEILLANCE RADAR; OCEAN CURRENTS; SATELLITE OBSERVATION; SYNTHETIC APERTURE RADAR; WAVE SCATTERING; BRAGG ANGLE; FOURIER TRANSFORMATION; MICROWAVE IMAGERY; SIGNAL TO NOISE RATIOS
Downloads: 171
[texts]F-16XL Wing Pressure Distributions and Shock Fence Results from Mach 1.4 to Mach 2.0 - Landers, Stephen F.
Chordwise pressure distributions were obtained in-flight on the upper and lower surfaces of the F-16XL ship 2 aircraft wing between Mach 1.4 and Mach 2.0. This experiment was conducted to determine the location of shock waves which could compromise or invalidate a follow-on test of a large chord laminar flow control suction panel. On the upper surface, the canopy closure shock crossed an area which would be covered by a proposed laminar flow suction panel...
Keywords: ACCELEROMETERS; FOURIER TRANSFORMATION; INTERNETS; SPECTROGRAMS; HISTOGRAMS; TIME SERIES ANALYSIS; SAMPLED DATA SYSTEMS; MICROGRAVITY; ACCELERATION MEASUREMENT; DATA REDUCTION; MISSION PLANNING; INTERPRETATION; DATA SAMPLING; FREQUENCIES; TIME DEPENDENCE
Downloads: 73
[texts]State-of-the-art cockpit design for the HH-65A helicopters - Castleberry, D. E.
In the design of a HH-65A helicopter cockpit, advanced integrated electronics systems technology was employed to achieve several important goals for this multimission aircraft. They were: (1) integrated systems operation with consistent and simplified cockpit procedures; (2) mission-task-related cockpit displays and controls, and (3) reduced pilot instrument scan effort with excellent outside visibility...
Keywords: HARMONIC MOTION; ION CHARGE; HEAVY IONS; ION DENSITY (CONCENTRATION); IONIC COLLISIONS; PAULI EXCLUSION PRINCIPLE; ABSORPTION CROSS SECTIONS; CHARGE DISTRIBUTION; CORRELATION; FOURIER TRANSFORMATION
Downloads: 89
[texts]The Guardian: Preliminary design of a close air support aircraft - Haag, Jonathan
One design is presented of a Close Air Support (CAS) aircraft. It is a canard wing, twin engine, twin vertical tail aircraft that has the capability to cruise at 520 knots. The Guardian contains state of the art flight control systems. Specific highlights of the Guardian include: (1) low cost (the acquisition cost per airplane is 13.6 million for a production of 500 airplanes); (2) low maintenance (it was designed to be easily maintainable in unprepared fields); and (3) high versatility (it can ...
Keywords: ELASTIC DAMPING; FOURIER TRANSFORMATION; HYSTERESIS; MECHANICAL PROPERTIES; MICROSTRUCTURE; MODULUS OF ELASTICITY; HEAT TREATMENT; METAL MATRIX COMPOSITES; NONDESTRUCTIVE TESTS; STIFFNESS; TEMPERATURE EFFECTS; VIBRATION DAMPING; VIBRATION TESTS; CERAMIC FIBERS
Downloads: 231
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